Geomechanical Characterization of Evaporitic Rocks

Abstract

This chapter aims to present a summary on the main physical and geomechanical properties of evaporitic rocks (evaporites), that is, sedimentary rocks of chemical origin composed mainly of chlorides, carbonates and sulfates such as halite, gypsum, anhydrite, sylvinite, carnallite, and calcite. This text deals with the geological definition of evaporites, formation environments, relevant sedimentary structures, and the diagenesis of sediments. All these aspects directly and indirectly influence the physical indexes of the rocks (density, porosity, water content, absorption, thermal conductivity, etc.) and the strength, deformation, and time-dependent properties. Specific aspects of the index properties of the aforementioned materials and their geomechanical properties will be dealt with, emphasizing the sulphate rocks formed by gypsum and anhydrite. Finally, real cases of geotechnical problems associated with these rocks will be presented.